Automatic cut-off valve



March 28,1939; J. A. RUMSEY 2,151,940

AUTOMATIC CUT OFF VALVE Filed Dec. 15, 1957 W TNESSES:

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Patented Mar. 28, 1939' PATENT OFFICE v 2,151,940 AUTOMATIC GUT-OFF VALVE John A. Rumsey, Swarthmore, Pa.

Application December 15, 1937, Serial No. 179,808

14 Claims.

This invention relates to automatic cut-oil valves in pressure lines and more specifically to valves of this character which are used in hydraulic brake systems of automobiles.

Automobiles using hydraulic brakes usually have a master cylinder which is operated by the automobile driver. This master cylinder is connected by pressure lines to the operating mechanism of the brakes on the wheels. Pressure on the master cylinder is instantly transmitted to the brake operating mechanisms and in this manner all the brakes are applied uniformly and simultaneously. As is well'understood, the whole system is filled with a liquid of some suitable.

l character but air must not be present in the system.; Obviously a very slight leak in the system v will seriously afiect'the operation of the brakes; and should any substantial amount of the liquid drain from the system, the entire system will 20 be rendered inoperative. The danger of an automobile whose braking system is rendered inoperative while in motion need not be mentioned.-

While the hydraulic brake system has many advantages, its one serious shortcoming is the vulnerability oi the entire system .from a leak or break in any portion of the system.

Accordingly the principal object of my invention is to provide a means for automatically segregating sections of the braking system in case of leaks or breaks and thus localizing the injury. Another object is the provision of a simple device in the system which will automatically close off parts of the system if a serious break or leak occurs in that part but which will not operate as a cut-off valve in cases of small and slow leaks. A further object isto provide a means 'of this character which has no springs orother resilient parts to get out of adjustment or break under wear. structure and operation, eflicient and easy readjustment after the automatic c it-oif valve has functioned, and positiveness of operation. Other objects and advantages will appear from the fol'-" lowing'detailed description of a preferred em- 45 bodiment of my invention, reference being had to the accompanying drawing.

,/ Fig. I of the drawing shows in a vertical longitudinal sectional view an automatic cut-ofl valve embodyingmy'invention, which is adapted for use in the hydraulic brake systems of automobiles.

Fig. II is a sectional view of the same taken as indicated by the arrows IIII in Fig. I.

Fig. III is a sectional view of the same taken as v 55 indicated by the arrows III-III in Fig. I.

Still-further objects are simplicity of" Fig. IV is a partial end view of the apparatus of Fig. I, partially in section.

Fig. V is a perspective view of 'the discharge element on which the valve member seats in closing.

Fig. VI is a perspective view of the valve member;

In describing the preferrred embodiment of my invention illustrated in the drawing, I shall resort to specific terminology for the sake of clarity. 10 However, I do not wish to be limited to the specific terms selected and I intend each specific term to include all technical equivalents which operate in a similar manner to accomplish a similar purpose.

In Fig. I, there is shown a diagrammatic representation of a master cylinder 1 of an automobile hydraulic brake system, connected at its discharge end to an automatic cut-oiI valve shown in section. This automatic cut-off valve which embodies my invention comprises generally a body 2, a cover member 3, discharge elements 4,'valve members 5, adjustment valve 6 and an end plate 1. The body 2 should be rugged in construction and may be made from any suitable metal as will be well understoodby the art.

It has formed therein two cylindrical cavities II which are of a proper diameterv to receive the discharge elements 4 with a press-fit. A supply conduit I2 is formed in the body 2 for connecting the master cylinder I to the cavities II which it does by means of conduit branches l4 and orifices I5. The branches. it may be vented to the atmosphere for bleeding'purposes by removing taps l6 provided for that purpose. A tubular opening is formed axially in the body 2 to re-' ceive the adjustment valve 6 snugly. but with capacity for controlled rotation. When the valve 6 has been moved to a position, it must remain there until moved again for adjustment 40 purposes.

The cover member 3 is bolted to the body 2 by means of bolts 20. In the cover member 3 are formed cavities 2| to receive the discharge from the discharge orifices 22 formed in the discharge elements 4. Ducts 23 are also formed in the cover member 3 for connecting cavities 2| to the pressure source as will be explained later, the ducts 23 being separated by the cavity formed to receive the end of the adjustment valve 6. The cavities 2| are provided with discharge openings communicating to the two separate parts of the hydraulic brake system through pressure front brakes; line 26 to the rear brakes.

The discharge elements 4 are cylindrical in shape and are positioned in the cylindrical cavities II with their outer ends flush with the cover member 3. The inner ends of these discharge elements 4 are beveled to provide seats for the valves 5. The length of the discharge element 4 is shorter than the cylindrical cavity H which provides space for the free floating of the valve 5. Each discharge element 4 has a group of four discharge orifices 22 positioned around a relatively large centrally placed dash pct 21. The discharge orifices 22 are of uniform diameter and extend completely through the discharge element 4. The dash pct 21 does not extend completely through the discharge element 4, but terminates in a relatively small restricted orifice or nozzle 28 which does extend through the discharge element 4, and connects the dash pot 21 with the cavity 2| in the cover member 3.

The valves 5 are square with arcuate corners which are formed on'the same diameter as the cylindrical cavities H. The square portions provide relatively restricted opening between the valve periphery and the surrounding cylinder walls which permits a small flow of liquid past the valve when open Without urging it to close. The underside of each valve 5 is beveled to cooperate with the valve seats formed in the discharge elements 4. A plunger 30 is also formed on the underside of each valve member 5, the plunger 30 being formed to fit into the dash pct 21. The valve member 5 should move easily in the cylindrical cavity II in order to function as a floating valve. The relation between the length of the cylindrical cavity H, the plunger 30 and the discharge element 4 should be such that when the valve 5 is in its extreme open position the plrttlnzgtr 30 will not be completely out of the dash D0 The adjustment valve 6 has formed thereinv an axial conduit 3| which is in registry with the supply conduit I2. This conduit 3| terminates at the cover end of the cut-out valve in a radially formed orifice 32 extending completely through the valve Sand so positioned that when the valve 6 is turned to a certain place the orifice 32 will connect the two ducts 23 to the source of pressure. At the other end of the valve 6 from the orifice 32 is another similarly formed orifice 29 at right angles to the orifice 32, and also extending all the way through the valve 6. The valve 6 is tapered at the end towards the cover member3andacrs 'isformdin.

0 re pending cavlty e tion and the key removed. The cut-off valve is the cover member 3 to receive this tapering end of the valve 6. The valve 6 ex nds through the cover member 3 and has a lug 34 on the end thereof which moves in the arcuate slot 35 formed in end plate I which is screwed in place on cover member 3. Thus the valve 6 by means of the lug 34 and slot 35 is limited in rotary movement. The valve 6 is turned by means of a key (not shown) which fits through an opening 36 in end plate I and into a similarly shaped groove 38 formed in the end of valve 6.

the valve 6 turned either to the right or left, the

key cannot be removed until the valve 6-is returned to its initial position with the groove 38 in registry with the opening 36. In the initialthe cut-off valve until the cut-off valve is placed Y through orifice 32.

When the end portion of the key is received in the groove 38 and well understood in the art. Line 25 leads to the in condition for normal operation. By turning the valve 6 to its extreme position in either direction the master cylinder is cut off from the conduit branches I4 but is continued open to the conduit 31 which communicates with ducts 23 It has been found desirable in practice to mount my automatic cut-01f valve in a position in which the valves 5 are gravity influenced toward the open position away from theelements 4. This counteracts any tendency of the valves 5 to close under vibration. When the valve 5 is of a comparatively light metal, I

, recommend that the plunger 30 be upright with the valve 5 urged open by gravity.

A description of the operation of the above described cut-off valve will further clarify the above structural description. In describing the operation, resort will be had to the terms upper and lower to designate the parts .of the cut-off valve associated functionally with the front and rear brake systems respectively. For example, the "upper valve 5 designates the valve 5 which controls the front brake system through pressure line 25 and it is the uppermost valve 5 in Fig. I. The upper valve 5 is shown in the normally operating position with the pressure line 25 in proper condition. The lower valve 5 is shown in the closed position, after a break has occurred in pressure line 26.

Before the break occurred in pressure line 26, the lower valve 5 floated freely in a position similar to that of upper valve 5. When the break occurred, thepressure was relieved in the pressure line 26 and the surge of fluid through the lower cylindrical cavity I I carried the lower valve 5 to the closed position as is shown in Fig. I. This immediately segregated the rear brake system from the master cylinder l and the rest of the brake system. Hence the front brakes con tinued to operate and very little fiuid and pressure was lost from the front part of the system.

The next consideration is the repair of the break in the rear part of the system. When this is accomplished, we then proceed to adjusting the cut-off valve to its operative position again. This is done by removing the lower tap l6 to open the vent and then rotating the adjustment valve 6 by means of a key until the pressure supply is connected to the lower dash pot 21 through the lower conduit 23, the lower cavity 2| and the lower nozzle 28. The pressure on the lower plunger 30 quickly moves the lower valve 5 to the full open position for it is opposed by atmospheric pressure only. The lower tap I6 is then replaced, the adjustment valve returned to its initial posinow ready for future operation.

Thus my invention provides a simple and efficient cut-off valve for installation in a pressure system such as a hydraulic brake system for automobiles. By means of my cut-oflz valve the system may be segregated into two or more parts and in that manner the part in which a break occurs becomes automatically segregated from the rest of the system and remains so until the break has been repaired and the valve re-adjusted for normal operation. The cut-off valve of my invention is simple in structure and avoids parts which wear quickly or get out of adjustment, such as springs and other resilient parts. A further very desirable characteristic of my invention is leaks which have only a gradually cumulative effeet on the operation of the system. Leaks of this character are not so serious because their pres:

that the cut-off valve does not operate for minor obvious.

ence is manifested before they have any serious eflect on the system but when a serious break occurs in a system equipped with the cut-off valve of my invention that portion of the. system is positively and completely shut off before theremainder of the system is adversely afiected. The importance of this in the case of automobiles is While I have described a specific embodiment of my invention in considerable detail, it will be obvious to one skilled in the art that many variations may be made in the specific embodiment described above without departing from the spirit .of my invention as hereinafter claimed.

Having thus described my invention, I claim:

1. In an automatic cut-oil valve for a pressure line, a cylinder, a valve operating in saidcylinder, a normally ineflective valve seat in said cylin- ,der to receive said valve in closing, and means v j said-vent.

for opposing the closure. of said valve consisting of a plunger attached to said valve, and a dash pot receiving said plunger, said dash pot havin a restricted orifice opening from its bottom end.

2. An automatic cut-off valve for a pressure line comprising a body, a normally ineffective valve operating in a cylindrical space in said body, a seat to receive said valve in closing, and meanafor opposing the closure of said ,valve con sisting of a plunger attached to said valve, and a dash pot receiving said plunger, said dash pot having a restricted conduit leading from its bottom portion into the discharge side of said valve.

3. An automatic cut-off valve comprising a body, a floating valve operating in acylinder formed in said body, aplunger attached to said valve,-'a dash pot receiving said plunger, said dash 6. The invention of claim 4 wher in a key is provided for turning said adjustmen valve, said key being incapable of removal until said valve is returned to its normal position.

I '7. The inventionof claim 4 wherein said a'd-. justment valve is provided with means for restricting' its turning capacity.

8. An automatic cut-off valve comprising a cylinder, a discharge element positioned in said cylinder, a floating valve positioned on the supply side of said discharge element, a seat formed on said discharge element to receive said valve, a

discharge orifice extending through said discharge not having a restricted nozzle connecting to the discharge side of said valve and an adjustment valve for admitting pressure to said dash pot said nozzle from the supplyside of said I through valve.

4. An automatic t-ofl valve, comprising a cylinder, a floating va ve operating in said cylinder, said valve being cut away at portions or its periphery, a plunger mounted on the discharge side of the valve, a dash pot receiving said plung er, a restricted orifice connecting the bottom portion ofsaid dash pot with the discharge side of said valve, an-adiustment valve for closing offthe supply side of said valve andadmitting pressure to the dash pot. 4

5. The invention of claim 4 wherein a vent to atmosphere is provided for said supply side of saidvalve and a closure member is provided for element, a dash pot formed in said discharge element, a plunger attachedto said valve and received by said dash pot, and a restricted orifice extending said dash pot through said discharge element.

9. The invention of claim 8 wherein an adjustmentvalve is provided for cutting of! the supply side of said valve from the pressure source and connecting the pressure source to said dash pot.

10. An automatic cut-oi! valve comprising a body, a cylinder formed in said body, a floating valve operating in said cylinder, a discharge element rigidly secured in said cylinder, said discharge element having a discharge orifice extendment, said plunger extending into said dash pot, a, cavity formed in said body to receive the discharge from said discharge element, said cavity having a connection for a pressure line, a nozzle connecting said dash pot with said cavity, a supparatus is duplicated and a common adjustmentvalve is provided for said cut-oil valve.

13. The invention of claim 10 wherein a vent is provided for said supply conduit and a removable cover is provided for said body affording access to theinternal elements of said valve.

14. The invention of claim 1 wherein said automatic 'valve' is mounted in a position which subiects said valve tothe force of gravity urging said valve toward the open position.

JOHN a. RUMSEY.

mg therethrough, a plunger mounted on said valve, a dash pot formed in said discharge ele- 

